How to make a pH tester out of red cabbage

How we made our pH indicator

Ingredients:

1/4 of a red cabbage chopped 

4 cups of distilled water (make sure cabbage is covered by the water)

Method:

Place cabbage and water into a big pot and boil until cabbage changes to a pale purple colour.

Strain the water off cabbage

Retain water as this is the pH indicator.